The present invention relates to a circuit breaker arrangement.
In the current medium voltage industry, the central removable switch cabinet plays a predominate role, and the primary characteristic thereof is that the circuit breaker can be separated from the switch cabinet. Based on the position of the circuit breaker within the switch cabinet, there are three different states: operating position, intermediate position and testing position. When the circuit breaker is at the operating position, the circuit breaker can be coupled with the main circuit of the switch cabinet; and when the circuit breaker is at the testing position, the circuit breaker maintains an isolation state from the main circuit of the switch cabinet. Wherein, the circuit breaker can only be drawn out from the switch cabinet when being in the testing position.
The movement of the circuit breaker can be achieved by a carrying cart. The existing carrying carts for the circuit breaker are mostly mounted onto the circuit breaker as an auxiliary for the circuit breaker. Such a conventional cart for the circuit breaker has become the only choice for most of the domestic switch cabinet companies. However, the existing carts for the circuit breaker present much problem as follows:
The cart and the circuit breaker are coupled into one entirety through bolt fastening, so that the circuit breaker and the cart wholly have a greater volume, are cumbersome, and the weight thereof is at least 15 kg, resulting in a higher package and transportation cost.
It has too little functions, lacks positional mechanical indication, has no emergency braking button and linkage dispersing, and the linkage for the low voltage plug is mounted on the switch cabinet. In addition, the existing cart also has no padlock and key lock.
In the swaying in/out process of the cart, the circuit breaker would be rocked, causing damage to the lead-screw.
The switching mechanism for the position switch is complicated, and the switching is unreliable.
The circuit breaker is swayable in/out when the door of the switch cabinet is in an open state, and the door can be opened when the circuit breaker is at intermediate position, which causing low safety.
The electrical arrangement is complicated to be implemented.
And according to a further aspect of the invention, an increasing number of medium-voltage switch cabinets requires electrodynamic mechanism, the operating position and isolated location of the circuit breaker accommodated in the cabinet is needed to have the ability of automatic switchover. Due to the possibility of the electrical motor occurring failure, it's necessary for the electrical motor to be able to facilitate assembly and disassembly, and at the same time, when manual operation is required, the electrical motor needs to be powered off. In the medium-voltage switch cabinet, the electrical motor driver mechanism, which drives the circuit breaker through the cart, generally moves along with the circuit breaker, and the electrical motor driver mechanism is commonly coupled with the drive lead screw of the cart via rack-and-gear. As such, additional 4 to 5 gears as well as chains would be added, and the transmission efficiency is lower, the adding of the chains also increases greatly the risk of failure. The cost is also increased. Using such a way that the electrical motor driver mechanism is cooperated with the drive lead screw of the cart, the circuit breaker will have to lifted by a crane when failure occurs for the electrical motor, the chassis, i.e., the aforementioned cart, is disassembled from the circuit breaker, then a screwdriver is used to unload the screw of the electrical motor and a new electrical motor is transferred to replace the used one, and the screwdriver is again used to fix the electrical motor onto the cart, then the cart is mounted to the circuit breaker.
It can be appreciated that such a manner, in which the electrical motor driving mechanism is coupled with the drive lead screw of the cart, makes it difficult to replace the inactive electrical motor, to perform assembly and maintenance, and further, the use of additional gears and chains would increase the manufacturing cost.
Thus, a drawback of conventional circuit breaker arrangements is that some heavy and cumbersome components are difficult to dismount and mount again on the cart of the cabinet, although this may become necessary for repair or replacement. The general purpose of this invention is to make easier the mounting and dismounting of these components with a modular construction of the circuit breaker arrangement.
According to a general definition, the invention relates to a circuit breaker arrangement, comprising:                a circuit breaker;        a cart on which the circuit breaker slides, the cart comprising a lead screw and a circuit breaker drive block, said drive block being threaded on the lead screw and driving the circuit breaker;        an electrical motor that rotates the lead screw;        characterized in that the circuit breaker and/or the electrical motor are mounted on the cart through connections consisting of interlocked parts, a latch for engaging one of the interlocked parts and maintaining said interlocked parts in an interlocked state, and a mechanism for releasing the latch.        
The connection between the cart and the separable modules comprising the circuit breaker and/or the electrical motor is based on an interlock of mating parts. The interlock can be made easily, by simple approach movements of the mating parts. When it is made, a right positioning of the modules on the cart is ensured. The latch safely maintains the interlock afterwards, until the mechanism is actuated. No complicated operations like installing and screwing bolts, or assembling the loose parts of a power transmission mechanism, are present in the invention.
When the invention is embodied for the circuit breaker module, the interlocked parts favorably comprise a protuberance on the drive block and an aperture in a floor of the circuit breaker, the protuberance entering the aperture in the interlocked state. The interlock can be made or interrupted by a mere movement of the protuberance, which may result from a rotation of the drive block. The circuit breaker module remains free on the cart when the interlock is interrupted and it may be removed by sliding on the cart upper surface. No particular accuracy is required from the operators.
Further, the latch may comprise static means provided on the cart for impeding a rotation of the drive block. Static means are likely to be safe and durable. An example consists in edges of an elongated slot parallel to the lead screw, said edges being adjacent to the protuberance, the elongate slot extending along a stroke of the drive block along the lead screw except at a disconnecting position for the circuit breaker. The disconnection of the circuit breaker module is possible only at a single position of the circuit breaker then, which could correspond to the testing position, and a safe connection of the module is ensured at the other positions, especially the operating positions.
The mechanism for releasing the latch may consist in means for rotating the drive block. This mechanism may depend on a handle normally not present on the apparatus, so that the unlatching only occurs with a voluntary action. It may be actuated by a particular rotation of the lead screw, either with the separate handle or with the electrical motor. In either case the unlatching occurs only when a determined position of the drive block is reached, which imposes a voluntary action anyway. In particular embodiments of the invention, this means comprises meshing elements provided on the drive block and on a support rotating with the lead screw. It may further comprise a guiding sleeve slidably and rotatably retained in a plate of the cart, a spring for biasing the sleeve at a set angular position and at a distance of the support, and the guiding sleeve comprises meshing elements which mesh with the elements of the drive block and of the support.
Also, the cart may comprise a front panel, which is provided with a handle inserting hole registering with a free end of the lead screw. The front panel may carry various knobs, warning lights, etc. for a convenient and elaborate operation of the apparatus. However, the handle inserting hole provides for the mentioned voluntary unlatching operation. This hole may remain obstructed during the normal operation of the apparatus.
When the invention is embodied on the electrical motor, the interlocked parts may comprise at least one pin and one mating pilot hole, the pin and the pilot hole being provided on a mounting first plate of the electric motor and on a second mounting plate provided on the cart. A better positioning is obtained with two pilot holes and two pins. This interlock is particularly easy to establish and to interrupt, with straightforward movements of the motor module.
In a particular embodiment, the second mounting plate is elbow-shaped, and the lead screw is provided with a third mounting plate, the third mounting plate being fixed to an upper side of the second mounting plate and the first mounting plate standing opposite another, vertical side of the second mounting plate. Such a construction facilitates an automatic coupling of the motor output shaft to the lead screw when the motor module is mounted to the cart. The coupling may include the engagement of a key (having a non-circular cross-section) into a mating keyway. A clutch may be present between the motor and the lead screw.
In such embodiments, the latch may simply comprise a mobile plate connected to a part in which the pilot holes are provided, and penetrating in grooves of the register pins, and the mechanism for releasing the latch may then comprise comprises a fourth mounting plate, and a pin provided on the fourth mounting plate and about which the mobile plate rotates.
In favorable embodiments of the apparatus, there is provided a swayable in/out driver mechanism for the circuit breaker, the driver mechanism comprises: a cart body which is fixed to the switch cabinet and does not move along with the circuit breaker in the switch cabinet; a lead-screw mounted onto the cart body by means of a lead screw anchor support and being only rotatable, wherein the lead-screw can be directly driven with a handle or electrical motor; a circuit breaker driver block engaged with the lead-screw, which moves forward and backward along the lead-screw under the rotation of the lead-screw, so as to bring the circuit breaker to switch between the operating position and the testing position, wherein when the circuit breaker is at the testing position, the connection or separation between the driver block and the circuit breaker can be achieved.
The driver mechanism further comprises: a front panel for the cart, which panel can protrude from the door of the switch cabinet so as to operate the circuit breaker and also comprises the functions of information indication and linkage.
The front panel for the cart comprises an emergency braking button, a padlock, a key lock, an insertion aperture for handle operation, an indicating device for the position of the circuit breaker and an indicating device for linkage state.
The emergency braking button comprises the following functions: (1) emergency braking, (2) improper operation proofing, and (3) mechanical and electrical block, and the emergency braking button has striking colors, and when the door is closed, operators perform operations to the emergency braking button through the pushing, moving and releasing operations.
The driver mechanism further comprises a handle slide for achieving the function where the circuit breaker can only be swayed in/out when the door is closed.
The driver mechanism also comprises a key lock, so that, only on occasions that it's unlocked in advance, could the handle slide be slid.
The driver mechanism can also control the driving operation through low voltage plug linkage, such that, when no low voltage plug is inserted, the cart can not be swayed.
The driver mechanism further comprise a gain on the door linking plate, so that when the circuit breaker is at the intermediate position, the gain on the door linking plate locks the stop pin on the door of the switch cabinet.
The driver mechanism is further provided with a grounding blade linkage associated with the grounding blade, such that, when the grounding blade is switched-on, the circuit breaker can not be swayed in, and when the circuit breaker is in the intermediate position, the grounding blade can not be switched-on.
When the circuit breaker is in the operating position, switching-on can only be enabled when the handle is drawn out.
The circuit breaker according to the present invention comprises the following advantages:
The cart has a much lighter weight which is ⅓ of that of the existing cart, and also has a lower cost than the existing cart.
The cart functions even more perfectly, integrates components which are previously arranged on the switch cabinet, such as the emergency braking button, linkage of the low voltage plug states, and is newly added with functions, such as a circuit breaker which is swayable in/out only when the door is closed, the door being unable to be opened when the cart is at the intermediate position, and status indication of the position of the circuit breaker and so on.
It's newly added with a key lock and a padlock, so that the safety is further improved.
An electrical motor may be directly mounted onto the lead-screw for driving the circuit breaker cart, so as to achieve motor driving.
The circuit breaker cart is mounted onto the switch cabinet, such that the transmission of the cart is more stable without any misalignment, and the cart and the circuit breaker are separated from each other, which enables more stable mechanical characteristics of the circuit breaker.
The forward and backward movement of the driver block for the cart provides for a more reliable switchover of the travel switch.
The present design concept differs obviously from existing chassis carts available on the market, existing problems may be avoided finely.
In other embodiments of the apparatus, there is provided a rack in/out mechanism having simple configuration and being easy for assembly and maintenance, the rack in/out mechanism is especially used for the circuit breaker in the switch cabinet, and also can be used for other apparatus mounted within the cabinet and required to be moved by the electrical motor. The most direct and effective way adopted by the present invention is to joint the drive lead screw of the driver unit for the circuit breaker directly with the electrical motor, no tools and screws are needed for the assembly and disassembly of the electrical motor. The technical solution for the rack in/out mechanism of the present invention is a rack in/out mechanism, which comprises an electrical motor, a retarding mechanism, a drive lead screw, a first mounting plate, a second mounting plate and a third mounting plate, the electrical motor drives the retarding mechanism to move, and the retarding mechanism is coupled with the drive lead screw to drive the drive lead screw, wherein both the electrical motor and the retarding mechanism are assembled onto the first mounting plate at the corresponding positions and are connected through the first mounting plate, the first mounting plate is provided with at least one register pin and/or at least one pilot hole, and both of the drive lead screw and the second mounting plate are fixed onto the third mounting plate at corresponding positions, the second mounting plate is provided with a pilot hole for receiving the register pin and/or a register pin for inserting into the pilot hole, the second mounting plate is fitted with the first mounting plate via the register pin and corresponding to pilot hole, and a output shaft of the retarding mechanism is directly jointed with the drive lead screw to drive the drive lead screw.
In this rack in/out mechanism, the electrical motor and the retarding mechanism are firstly positioned on the first mounting plate at corresponding positions, the drive lead screw and the second mounting plate are positioned on the third mounting plate at corresponding positions, the corresponding positions mean the where the rack in/out mechanism can achieve its functions, and based on different types and models of the adopted electrical motor, the retarding mechanism and/or the drive lead screw, such corresponding positions may be properly regulated to suit different requirements. By means of the register pins and pilot holes respectively provided on the first mounting plate and the second mounting plate and by arranging the positions thereof, it's possible to directly joint the output shaft of the retarding mechanism with the drive lead screw. Using the rack in/out mechanism with such an arrangement, the assembly of the electrical motor and its retarding mechanism is independent of the drive lead screw, and jointing with the drive lead screw may be made after the assembly of the electrical motor and the retarding mechanism, thus when failure occurs for the electrical motor or the retarding mechanism, the electrical motor and the retarding mechanism may also be directly decoupled from the drive lead screw, thereby the service and maintenance for the electrical motor is unlikely influenced by the positions of the drive lead screw and the positions of the devices driven by the drive lead screw, facilitating the replacement of the faulted electrical motor. Moreover, such a rack in/out mechanism provides a simple and reliable manner for transmitting power, by which desired velocity ratio can be obtained through selecting a favorable retarding mechanism, and the retarding mechanism may be the conventional existing products, which reduces the production cost.
Preferably, the electrical motor and the retarding mechanism are mounted onto the first mounting plate at opposite two sides, the output shaft of the electrical motor drives the retarding mechanism to move, the second mounting plate is elbow-shaped or ‘┌’-shaped, a side of the ‘┌’ shape is fitted on a side of the third mounting plate, and the other side mates with the register pin and/or pilot hole on the first mounting plate through the pilot hole and/or the register pin located at this side, the drive lead screw is positioned at opposite another side of the third mounting plate, the positions of the drive lead screw, the register pin and the pilot hole, the third mounting plate, the second mounting plate and the first mounting plate are arranged in such a way that when the register pins mate with the pilot holes and the rack in/out mechanism is kept in an assembled state, the output shaft of the retarding mechanism is directly jointed with the drive lead screw.
Preferably, the coupling between the retarding mechanism and the drive lead screw is achieved through a clutch. By achieving the connection between the retarding mechanism and the drive lead screw via a clutch, it's easy to achieve the connection and disconnection of the power transmission between the retarding mechanism and the drive lead screw.
Preferably, the retarding mechanism and the clutch are integrated into a housing to create a power transmission mechanism for transmitting the power from the electrical motor, for inputting power to the drive lead screw. With the integration of the retarding mechanism and the clutch, module production is facilitated, and according to the requirement for power input by the drive lead screw, it's possible to select the suitable power transmission mechanism and electrical motor. Preferably, at least a portion of the end of the output shaft of retarding mechanism is a polygonal output shaft, the end of the drive lead screw is formed with a polygonal hole for receiving the polygonal output shaft, the polygonal output shaft cooperates with the polygonal hole so as to transmit the power output from the output shaft of the retarding mechanism to the drive lead screw and rotate the drive lead screw. By designing a portion of the end of the output shaft of the retarding mechanism to be a polygonal output shaft, and the end of the drive lead screw being formed with a polygonal hole for accommodating the polygonal output shaft, it's possible to cooperate the polygonal output shaft with the polygonal hole, thereby the power transmission between the retarding mechanism and the drive lead screw can be achieved by such a cooperation, driving the drive lead screw to move.
Preferably, at least a portion of the end of the drive lead screw is a polygonal output shaft, the end of output shaft of the retarding mechanism is formed with a polygonal hole for receiving the polygonal output shaft, the polygonal output shaft cooperates with the polygonal hole so as to transmit the power output from the output shaft of the retarding mechanism to the drive lead screw and rotate the drive lead screw. With such a design, it's still possible to achieve the power transmission between the retarding mechanism and the drive lead screw, thus driving the drive lead screw to move.
Preferably, the polygon is a regular hexagon, a square or an equilateral triangle.
The regular hexagon, the square and the equilateral triangle are shapes easy to be machined. Preferably, at least a portion of the end of the output shaft of the retarding mechanism is formed with key outward protruding from the output shaft, and the end of the drive lead screw is formed with keyway for receiving the key, and by the cooperation of the key and the keyway, the power output from the output shaft of the retarding mechanism is transmitted to the drive lead screw and rotates the drive lead screw.
Preferably, the rack in/out mechanism is further provided with a rotating side plate which is fixed to the fourth mounting plate via a rotary pin and may pivot around the rotary pin, the fourth mounting plate and the side of the second mounting plate provided with the register pin and/or the pilot hole are connected together, the first mounting plate is provided with two register pins or two pilot holes, and the second mounting plate is provided with two pilot holes or two register pins corresponding to the two register pins or two pilot holes on the first mounting plate, the register pin is formed with a groove, the shape and position of the rotating side plate are designed in such a way that when the rotating side plate is rotated to a certain position, the edge of the rotating side plate is caught into the groove of the register pin to lock the first mounting plate and the second mounting plate.
By designing the fourth mounting plate and the rotating side plate with such a configuration, the edge of the rotating side plate may be caught into the groove of the pin when the rotating side plate is rotated, thus the first mounting plate and the second mounting plate is locked, and in such an assembly manner, it's possible to lock the first mounting plate and the second mounting plate without requiring the connecting manner, such as threaded connection, soldering and the like, allowing for simple assembly and disassembly manners, the rotating side plate is only required to be rotated in opposite direction to unlock the relative fixation between the first mounting plate and the second mounting plate.
Preferably, the rotating side plate is provided with a knob for facilitating the rotation of the rotating side plate.
The knob provided on the rotating side plate makes it convenient for the user to rotate the rotating side plate, thus meeting the human engineering design.
Preferably, the rack in/out mechanism is used for a circuit breaker driven by a cart, and the cart is driven by a driver block provided on the drive lead screw, which driver block transforms the rotary motion of the drive lead screw into linear motion.
Preferably, the third mounting plate is a baseplate of the switch cabinet for accommodating the circuit breaker.
The rack in/out mechanism is especially adapted to be used for the driving of the circuit breaker driven by a cart within the switch cabinet, and overcomes the deficiencies in prior art that the electrical motor of the cart for driving the circuit breaker is difficult to repair and has lower transmission efficiency.
There is also provided a method for assembling the above rack in/out mechanism, comprising steps as follows, assembling the electrical motor and the retarding mechanism together through the first mounting plate, assembling the drive lead screw and the second mounting plate onto the third mounting plate, assembling the fourth mounting plate and the rotating side plate together, then assembling the fourth mounting plate and the second mounting plate together, positioning the assembled electrical motor and the retarding mechanism by the cooperation between the register pin and the pilot hole, directly jointing the output shaft of the retarding mechanism with the drive lead screw, then rotating the above-mentioned rotating side plate to lock the first mounting plate and the second mounting plate.
By assembling the second mounting plate and the third mounting plate as well as assembling the second mounting plate with the fourth mounting plate, which assembling are all achieved by threaded connection, the holes through which the bolts pass are aligned with each other by the above cooperation, thus it's possible to achieve firstly positioning the second mounting plate on the third mounting plate at appropriate position, and then positioning the fourth mounting plate on the second mounting plate at appropriate position, generally the third mounting plate is commonly an unmovable plate, hence, by selecting the position of the holes through which the bolts pass, the second mounting plate and the fourth mounting plate may be well placed at desired positions, so as to eventually achieve the directly jointing of the output shaft of the retarding mechanism with the drive lead screw.
The rack in/out mechanism according to the present invention overcomes the weakness of the rack in/out mechanism in prior art that the electrical motor thereof is difficult to repair and replace, while providing higher transmission efficiency and lower manufacturing cost.
A detailed description of an embodiment of the invention with reference to the figures beings now.